Comparing two psychological interventions in reducing impulsive processes of eating behavior: Effects on self-selected portion size

Abstract

Because eating behavior can take on an impulsive nature many people experience difficulty with dieting to lose weight. Therefore, an experiment was conducted to test the effectiveness of two interventions targeting impulsive processes of eating behavior to facilitate weight loss: Implementation intentions to remind people about dieting versus a go/no-go task to change impulses toward palatable foods. Dieters performed an online training program (four times in 4 weeks) in which they were randomly assigned to a 2 (implementation intention condition: dieting versus control) x 2 (go/no-go task condition: food versus control) design. They formed either dieting implementation intentions (e.g., If I open the fridge I will think of dieting!) or control implementation intentions. Furthermore, they received either a go/no-go task in which behavioral stop signals were presented upon presentation of palatable foods (food go/no-go task), or upon control stimuli. Participants' weight was measured in the laboratory before and after the intervention. Strength of participants' dieting goal and their Body Mass Index (BMI; as a proxy for impulsiveness toward food) were examined as moderators. Results showed that both dieting implementation intentions and the food go/no-go task facilitated weight loss. Moreover, dieting implementation intentions facilitated weight loss particularly among people with a strong current dieting goal, whereas the food go/no-go task facilitated weight loss independent of this factor. Instead, the food go/no-go task, but not formation of dieting implementation intentions, was primarily effective among dieters with a relatively high BMI. These results provide the first preliminary evidence that interventions aimed at targeting impulsive eating-related processes via the internet can facilitate weight loss.